(a) Field of the Invention
The present invention relates to a novel apparatus for continuously cooking and leaching food pieces with a cooking liquid such as water at an elevated temperature and is particularly concerned with the gentle handling of fragile food pieces during leaching or cooking in solvents or liquids, such as water, with the application of heat and with the controlled contact of mechanical transfer means and leaching medium so as to avoid degradation of fragile food pieces.
(B) Description of the Prior Art
Numerous apparatuses have been disclosed in the prior art for continuously cooking or otherwise treating food. As an illustration, U.S. Pat. No. 3,886,856 discloses an apparatus for continuously cooking grain under pressure by utilizing a conveyor belt having a plurality of conveying members and a pair of restriction members which form a fluid pressure seal with the conveyor members at predetermined locations along the path of travel of the conveyor so that the grain can be added to and discharged from a pressure cooker without loss of pressure. U.S. Pat. No. 3,807,293 discloses a conveyor type oven having an endless conveyor and trays attached thereto, which are inverted at the ends of the conveyor. Each tray after passing through the oven and upon reaching the end of the conveyor is adapted to pour its contents into a screw conveyor, then the tray is inverted as the conveyor returns under the oven. During their return, the inverted trays are washed and rinsed.
U.S. Pat. No. 3,782,269 discloses a continuous omelet preparing machine which comprises a plurality of forms on which the omelet batter is deposited, cooked and folded and an endless conveyor on which the forms are mounted and moved. After passing through the heating means and following folding, the omelets are discharged and the forms are returned on the endless conveyor by passing underneath the heating device. On their return trip the forms are washed, rinsed and dried.
U.S. Pat. No. 3,223,024 discloses an apparatus for washing and cooking potato chips in a continuous fashion. The apparatus disclosed in this patent utilizes a hot oil bath wherein the oil is withdrawn, reheated, recycled back to the bath while the potato chips on the conveyor belt are caused to move from one end of the bath to the discharge end. The oil is withdrawn from the bath at the discharge end, reheated and returned at the inlet end of the bath resulting in concurrent flow of potato chips and hot oil.
No prior art is currently known to disclose or teach apparatus or method of cooking large quantities of relatively fragile food pieces in a gentle manner on a large scale. No prior art is currently known which utilizes as a means for heating a cooking vessel, a plurality of means along each side of the vessel for withdrawing cooking fluid from it, heating the fluid and returning it to the vessel along the center line thereof. An arrangement such as this provides gentle handling of very fragile food pieces and results in a reduced production of fines. It also permits more precise control of temperature during large scale cooking operations and averts overcooking or under cooking of the food pieces or portions thereof. It allows the establishment of a temperature profile along the length of the cooker. For example, the temperature in those areas where fresh cooking liquid (e.g., hot water) contacts the food pieces can be kept relatively lower than the temperatures in those areas where the cooking liquid contains relatively high amounts of extractables since higher temperatures increase the extraction rate.